Drawbench arm mechanism



Feb. 13, 1945. E R 7 2,369,467

DRAWBENCH ARM MECHANISM Filed Oct. 2, 1942 2 Sheets-Sheet 1 INVENTOR Wad/ace [Li/(err.

' 33 37 A ORNEY Feb. 13, 1945. w. E.'KERR 2,369,467

DRAWBENCH ARM MECHANISM Filed Oct. 2, 1942 2 Sheets-Sheet 2 INVENTOI-R igcy/a ce Kerr.

Patented Feb. 13, 1945' UNITED STATES, PATENT OFFICE DRAWBENCH ARM MECHANISM Wallace E. Kerr, Youngstown, Ohio Application October 2, 1942, Serial No. 460,519

26 Claims.

This invention relates to a drawbench arm mechanism and more particularly to an improved arrangement for operating work discharge arms in relation to the grip bit carriage of a drawing machine.

Heretofore, it has been proposed to provide a number of discharge arms spaced longitudinally along the drawbench and mounted for swinging movement about generally vertical axes positioned to one side of the line or draw. The arms are each provided with a sloping top so that when the same are positioned laterally across the drawbench and underneath the work being drawn the work will roll oil the arms upon being released from the die and grip bits. This mode of operation requires that all the arms be rotated into retracted positions to one side of the drawbench upon the return movement of the grip bit carriage and that the respective arms be rotated in the opposite direction into positions underneath the work as the grip bit carriage moves by them in its outward or drawing movement.

The primary object of the invention is the provision of a practical and substantially simplifled arrangement for operating the arms whereby the above outlined mode of operation may be effected. This general object is accomplished, in accordance with the preferred embodiment of the invention, by employing the grip bit carriage return cable to furnish the directive power required to move or rotate the arms in the proper direction, and at the proper time required in the sequence of operation of the drawing machine.

A more specific object of the invention is the provision of an improved and more rugged driving interconnection between the cable above mentioned and the respective arms whereby the power required to be applied to the cable for the purpose of operating the arms is substantially reduced and the possibility of peakedshock loads being applied to the cable is minimized.

A further object of the invention is the provision, in drawing machine having work discharge arms arranged to be rotated into and out of the path of travel OLf the grip bit carriage, of an arrangement whereby the speed of travel of the carriage in the direction toward the die holder will be automatically reduced in the event that any one of the arms is in the path of travel of the carriage. This feature materially reduces the danger of injuring either the arms or any part of the carriage regardless of the speed of operation of the drawing machine.

The above and other objects and advantages of th invention will become apparent upon a consideration of, the following detailed specification and the accompanying drawings wherein there is specifically illustrated,- .a preferred embodiment of the invention.

In the drawings:

Figure 1 is a plan view, schematic in part, of a portion of a drawing machine constructed in accordance with the principles of the invention;

Figure 2 is a fragmentary side elevation of the apparatus of Figure 1, showing the return cable driving arrangement;

Figure 3 is a side view, on an enlarged scale,

of a ortion of the apparatus of Figure 1, the" view looking in the direction of the arrows 3-3 of Figure 1;

Figure 4 is a plan view of the apparatus of Figure 3; a

Figure 5 is a transverse section along the line 5--5 of Figure 6; and i Figure 6 is a transverse section, on an enlarged scale, through the apparatus and along the line 66 of Figure 1.

In the drawings, reference numeral [0 designates the rails or tracks of a drawbench on which is movably mounteda grip bit carriage I l. The die block is shown schematically at [2, a bar being drawn at l3, and the draw chain at M. Arranged to extend across the drawbench below the work being drawn and intermediate the carriage II and the die block l2 are a plurality of -work discharging arms 15 only two of which are shown in Figure 1 but it should be understood that in actualpractice a greater number of arms are employed, being spaced, [for example, approximately six to eight feet along the longitudinal extent of the bench.

As shown in Figures 3 and 6 eachof the arms is provided with a sloping top surface ,and is carried by and keyed to a shaft l6 which is antifrictionally journaled in a bracket ll. The latter in turn is carried by a member l8 which. is rigidly bolted at I!) to one of the side beams 20 of the drawbench bed construction, a pivotal connection being provided between the bracket I1 and member 18 by a horizontally disposed pivot pin 2| to allow the bracket I! to have limited rotational movement in a clockwise direction as viewed in Figure 6 so that an excessive downward thrust on the arm l5 will move the arm downwardly into engagement with the guides 22 of the bed construction. Normally, however, the weight of the bracket ll. the shaft 16 and thearm l5 maintains the parts in their positions shown in Figure 6.

Keyed to the lower end of shaft I6 is a diskand I6.

like member 23 having a circular lower plane face 24 and outwardly extending wings 25 and 26. The wings 25 and 26 are arranged to alternately engage one or the other of the two resilient bumper blocks 21 which are secured to the bracket l1. As shown in Figure the blocks 21 and wings -26 are designed to allow shaft |6, and consequently arm I5, to rotate approximately 90 and upon the arm reaching the end of this movement in either direction the inertia or impact is absorbed by one or the other of the blocks 21. In one limiting position the arm is parallel with the drawbench and outside the path' of travelof the carriage as illustrated by the left arm of Figure 1 while in the other limiting positionrthe arm extends across the drawbench as illustrated by the right arm of Figure 1.

Associated with each of the arms I5 is a driving mechanism assembled on a frame 28 which frame may be either attached or carried by the drawbench proper or anchored to an independent foundation in proper alignment with the shaft l6. Vertically extendingshaft 29 is anti-frictionally journaled in frame 28 by means of combined radial and thrust bearings. To the upper end of shaft 29 is keyed a collar 3|! having an end flange 3| providing a flat round top surface of considerable area to oppose the lower fiat surface of the member 23 which is keyed to the shaft l6. It will be noted that the axis of shaft 29 is aligned with the axis of shaft l6. A disk of friction brake material 32 is riveted or otherwise suitably secured to the member 30 to provide a friction driving connection between the shafts 29 pressure between surface 24 and lining 32 as represented by the moment tending to rotate the bracket l1 and arm l5 assembly in a counterclockwise direction as viewed in Figure 6. This moment is substantial--resulting from the weight of shaft I6 and disk 23 and from the weight of the majority part of the bracket H and arm l5.

To the lower end of shaft 29 is keyed a gear 33 which meshes with a pinion 34 keyed to the lower end of a slightly tilted shaft 35 to the upper end of which is keyed a double grooved pulley 36. On the diametrically opposite side of shaft 29 from the shaft 35 is another shaft 31 tilted oppositely from the shaft 35. Shaft 31 also carries at its upper end a double grooved pulley 38 which is identical with the pulley 36.

The preferred and illustrated embodiment of the invention includes, in accordance with usual practice, a grip bit carriage return cable 39 which is attached to the grip bit carriage and reeved over pulleys 40 and 4| positioned at opposite ends of the drawbench. One of these pulleys, as the pulley 4|], is arranged to be driven by a motor 42 for the primary purpose of quickly returning the carriage I to the die block l2 upon the completion of a drawing operation as is well understood in the art. In accordance with this invention, however, the grip bit carriage return cable is also reeved over the pulleys 36 and 38 to provide for the transmission of power to operate the work discharge arms 65. This is clearly indicated in Figures 1-4 and 6 of the drawings and it should be apparent that the arrangement of the oppositely tilted pulleys 36 and 38 reduces wear and friction in the cable to a minimum.

Referring now more particularly to Figures 3 and 4 of the drawings, a latch collar 43 is also keyed to the shaft l6, being positioned below the hub of the arm I5, or it may be an integral part of the arm l5. Cooperating with latch 43 The pivotal connection 2| provides a is a spring presseddog' (Figure 4) which is operative to retain the latch and arm in the position the parts are shown in Figure 4. Dog 44 is provided with a projection 45 arranged to be engaged by a gate type operator 46 mounted on the carriage ll. 'As shown in Figure 3, operator 46 is free to move in a clockwise direction but is blocked against opposite movement by the stop 41. Thus during outward or drawing movement of the carriage, as indicated by the arrow in Figure 1, the operator 46 is operative to rotate the dog 44 in a'counter-clockwise rotation (Figure 4) against the pressure of the biasing spring to release the latch thereby allowing the arm to swing into discharging position across the drawbench while during opposite movement of the carriage the operator 46 merely over-rides pro- Jection 45 of dog 44.

Associated with each of the discharge arms is a normally closed switch 48 having an operator 49, which switch is mounted on a projection 50 extending outwardly from the bracket [1. The operator 49 of switch 48 is arranged to be engagedby an adjustable element 5| carried by the depending part of the projection 45 of the dog 44 and the arrangement of the parts is such that the switch remains closed when the dog is in latching position as shown in Figure 4 but is opened when the dog is in a counter-clockwise position as it would be if the arm I5 were extended into the path of travel of the carriage.

By way of illustration, the motor 42 is shown as being of the shunt wound direct current type deriving its energy from the line Ll, L2. In series with the energy supply line is a contactor SI arranged to be closed upon the energizatlon of a solenoid SOI which is connected across the line LI, L2 through conductor 52, switch 53, conductor 54, conductor 55, switch 56, and conductor 51. Switch 53 may be either a manually 0perated return push button or an automatically operable switch, depending on the character of operation of the machine, and switch 56 may be either a manually operated (stop) push button or an automatic switch which is arranged to be opened as the carriage approaches the die block. Also operated by solenoid SOI is a second contactor S2 arranged to establish the holding circuit conductor 58, switch S2, conductor 59', and

conductor 60 to LI upon the momentary closing of switch 53.

In series with the motor energizing line and thev armature of the motor 42, through conductor 64, is the starting resistance R which, as will be understood, limits the starting current flowing through the armature. In accordance with the usual practice, the starting resistance'R is arranged to be cut out, normally, when the armature reaches a predetermined speed and develops sufficient counter E. M. F. to effectively limit the armature current. For this purpose resistance R, is arranged to be shunted by the contactor S3 operated by the solenoid S02. The energizing circuit for this solenoid is in parallel with the armature circuit so that upon a predetermined restoration of the voltage across the line, resulting from the attainment of the predetermined armature speed, the contactor will be pulled in and the resistance out out.

In accordance with the preferred and illustrated embodiment of the invention the switches 46 are connected in series with each other and in series with the energizing circuit for coil S02 through conductor 6|, conductor 62 (it being assumed that more than two arms are in operation), and conductor 83. Thus so long as each and all of the switches 48 are closed, i. e., the

In operation, with the parts positioned as shown 2 in Figure 1 during a drawing operation, as the carriage passes the left arm the operator 48 will ,rotate dog 44 of this arm and the cable, which moves whenever the carriage moves as is apparent from Figure 2, will thereupon swing this arm across the drawbench, the; chain of drive including the pulley 36, shaft 35, pinion 34, gear 33, shaft 29, clutch 24- -32, and shaft I6. While the carriage is movingand before'the latch 43, 44 is released the clutch 24-42 simply slips.

When the grip bit carriage ll reaches the end of its outward or drawing stroke all the arms intermediate it and the die l2 will be in dis charging position and upon the release of the work from the die and the grip bits the work will roll or slide down the sloping tops of the arms and thus be discharged. At this time the switch 53 is closed, either manually or automati-' cally, to energize motor 42, in the manner explained above, to return the carriage back to the head block I2. This reverses the direction of movement of the cable 39 and immediately all the arms are rotated to their retracted positions and latched in place by the dogs 4-4. This rotational movement of the arms l5 takes place while the motor is operating at reduced speed and, as explained above, unless all the arms are moved out of the way of the carriage the motor will not accelerate to its full speed. This feature avoids the possibility of damaging impacts be-' tween the carriage and arms.

It should now be apparent that I have provided an eflicient and rugged drawbench arm construction which accomplishes the objects initially set out. The speed reduction provided by the pulleys 36 and gear sets 33-34 enables sati factory operat on to be attained without materially increasin the size of the grip bt carriage return motor. The driving clutch arrangement 23, 24, 29-32 is simple in design and construction and rugged in use. Its pressure loading is entirely automatic and the construction has the further important advantage of entirely disconnect ng the shaft l6 from its drive thereby allowing the arm l5 and its support to tilt about a horizontal axis when an excessive downward thrust is applied to' the arm.

The above specifically described embodiment ,of the invention should be considered as illustrative only as obviously many changes may be made therein without departing from the spirit or scope of the invention. For example, the specific direct current motor M shown may obviously be replaced by another type of motive power and the switches 48 may be controlled directly by the positions of the respective arms. Reference should therefore be had to the appended claims in determining the scope of the invention.

What I claim is:

1. Incombinationwith a drawbench having a stock Working device, and a draw grip movable along the bench toward and away from said device. a rotatable support positioned outs de the path of travel of said grip, a discharge arm fixed tosaid support and adapted to be moved thereby from retracted position outside the path of travel of said grip to discharging position extending across the bench and vice versa, and means connected with the grip operable to continuously rotating said support.

tend to rotate said support in a direction to move said arm from retracted to discharging. position only during movement of said draw grip away from said device. p

2. Apparatus according to claim 1 further including a common moving means for moving said grip in a direction toward said device and for 3. In combination with a drawbench having a. stock working device and a draw grip movable relatively toward and away from eachother, a rotatable support positioned outside the path of travel of the movable member, a discharge arm.

fixed to said support and adapted to be moved thereby from retracted position outside the path of travel of the movable member to discharging position across said path and vice versa, and means operable to continuously tend to rotate said'support in a direction to move said'arm to discharging position only 'duringrelative movement of said device and draw grip.

4. In combination with a drawbench having a stock working device and a draw grip movable.

5. In combination with the drawbench having a stock working device and a draw grip movable relatively toward and away from each other, a discharge arm mounted for movement from retracted position outside the path of travel of the movable member to discharging position in said path and vice versa, means to move said device and draw grip relatively toward each other, means to move said arm from discharging to retracted position, and means operable upon the arm reaching a retracted position to increase the speed of the means to relatively move said device and grip toward each other.

6. In combination with a drawbench having a stock working device and a draw grip device movable relatively toward and away from each other,

a discharge arm mounted for movement from retracted position. outside the path of travel of the movable member to discharging position in said path and vice versa, means connected with one of said devices operable to continuously urge said arm into discharging position only during separating relative movement of said devices, and

means mounting said arms for limiting downward movement when in dischargin position whereby the arm when in such position may be forcibly depressed to diminish downward impact on the arm.

7. A discharge armfor a drawbench mounted for movement from retracted position to discharging position and vice versa, means connected with said arm for so moving said arm. said mounting means being operable to allow limited downward movement of said arm when in discharging position whereby said arm may be forcibly depressed to diminish downward impact on the arm, and means to automatically disconnect said arm from its moving means when said arm is so depressed.

8. A drawing machine having a stock working device, a draw grip, means to move said device and grip apart to effect a draw, means comprising a cable to move said device and grip toward each other; a discharge arm mounted for movement from retracted position to discharging position below the work intermediate the ,device and grip and vice versa, and a speed reducing driving connection between said cable and said arm whereby movement 'of said cable effects movement of said arm to retracted position.

9. Apparatus according to claim 8 further characterized in that said driving connection includes a slip clutch whereby said arm may be completely retracted during the first portion of the movement of the cable.

10. A drawing machine having a stock working device, a draw grip, means to move said device and grip apart to effect a draw, means comprising a cable to move said device and grip toward each other, a discharge arm mounted for movement from retracted position to. discharging position below the work intermediate the grip and device and vice versa, a driving connection between said cable and said arm whereby movement of said cable in one direction results in movement of said arm to retracted position, and mean responsive to the position of said arm in control of the speed of said means to move said device and grip toward each other.

11. A drawing machine having a stock working device, a draw grip, means to move said device and grip apart to effect a draw, means comprising a cable to move said device and grip toward each other, a vertically extending shaft rotatably mounted to one side of the line of'draw, a discharge arm fixed to said haft, means to rotate said shaft whereby said arm may be moved from retracted to discharging position and vice versa, said last mentioned means comprising a sheave arranged to be reeved by said cable and a yield able driving-connection intermediate said sheave and said shaft.

12. A discharge arm construction for a drawbench having an elongated frame and a carriage movable therealong, a bracket secured to one side of said frame, an upwardly extending shaft journaled in said bracket, a discharge arm fixed to the upper end of said shaft, a resilient bumper block secured to said bracket, a member rotatable with said shaft and arm adapted to engage said block to limit rotation of said arm to an arc of approximately 90, and means comprising a clutch connected to the lower end of said shaft to rotate said shaft.

13. A discharge arm construction for a drawbenchhaving an elongated frame .and a carriage movable therealong comprising a bracket secured to one side of said frame, an upwardly extending shaft journaled in said bracket, 9. discharge arm keyed to the upper end of said shaft, a driven ,clutch member keyed to the lower end of said shaft, and an over-running driving clutch member for engaging said driven member.

14. Apparatus according to claim 13 further including means comprising a cable to move said carriage along said frame and to drive said over-running clutch member. 7

15. Apparatus according to claim 13 further including means comprising a cable to move said carriage along said frame, a support below said bracket, a shaft journaled in said support in axial alignment with said first mentioned shaft and carrying said driving clutch member for coacsupport to rotate said second mentioned shaft upon movement of said cable.

16. Apparatus according to claim 13 further characterized in that said bracket is pivotally connected to said frame whereby said bracket may be tilted about a generall horizontalaxis extending parallel with said frame and further including a support positioned below said bracket, said driving clutch member being rotatably carried by said support in axial alignment with said first mentioned shaft, and means to rotate said driving member, said driving and driven members being readily separable whereby said bracket and arm may be tilted without disturbing said support and driving member.

17. In a discharge arm construction for a drawbench an' upwardly extending shaft, a discharge arm secured to the upper end of said 'shaftfmeans to limit rotation of said shaft to approximately 90 and to cushion the impact of the shaft and arm as 'the same reaches the end of the travel in either direction, a continuously moving element tending substantially at all times to rotate said shaft in one or the other direction, and a yieldable driving connection between said element and shaft.

18. Apparatus according to claim 17 further including a latch to retain said arm in retracted position during movement of said element. in a direction tending to move said arm to discharging position, and means responsive to the position attained by the drawbench carriage during its drawing stroke to release said latch.

19. In a discharg arm construction for a drawbench an upwardly extending shaft, a discharge arm secured to the upper end of said shaft, means to limit rotation of said shaft to approximately 90 and to cushion the impact of the shaft as the same reaches the end of its travel in either direction, a continuously moving element tending substantially at all times to rotate said shaft in one or the other direction, a yieldable driving connection between said element and shaft, a latch to retain said arm in retracted position during movement of said element in a direction tending to move said arm to discharging position, means to release said latch, and means responsive to the position of said latch to vary the speed of said moving element.

20. A discharge arm construction for a drawbench comprising a support and a discharge arm movably carried thereby, means to move said arm from retracted to discharging position and vice versa, a friction clutch intermediate said moving means and said arm, said support being so mounted with relation to said moving means that the pressure loading on said clutch results from the weight of a substantial portion from said support and arm.

21. In combination with a drawbench having a stock working device and a draw grip movable relatively toward and away from each other, a vertically disposed shaft, a discharge arm keyed to said shaft and operative upon rotation of said tion with said driven member, and means on said shaft to be moved from retracted position out- 23. A discharge arm construction for a drawbench having an elongated frame and a carriage movable therealong comprising a bracket secured to one side of said frame, an upwardly extending shaft journaled in said bracket, a discharge arm fixed to the upper end of said shaft, a driven clutch member fixed to the lower end of said shaft, and an over-running driving clutch member for engaging said driven member, the clutch comprised of said driving and driven members having the characteristic of tending to transmit more torque when said discharge-arm moves and less torque when said am is stationary.

24. In combination with a drawbench having a stock working devic and a draw grip movable relatively toward and away from each other, a vertically disposed shaft, a discharge arm fixed to said shaft and operative upon rotation of said shaft to be moved from retracted position outside of the path of travel of the movable member to discharging position in said path and vice asoaact versa,.and means to rotate said shaft, said means ment of the device and grip toward each other.

- ing device, a draw grip device, means to move comprising adriving memberand speed reducing mechanism as well as an impositive driving interconnection between said driving member and said shaft whereby the torque required to initiate rotation of said shaft and .to continue rotation of said shaft is reduced.

25..In combination with a drawbench having a stoclr'working device and a draw grip movable relatively toward and away from each other, a drawn stock discharge arm movable into and out of the path of movement of the movable memher. and means to move said arm comprising a cable extending entirely along one. side of said bench and means to move said cable in opposite directions.

26. A drawing machine having a stock worksaid workingdevice and grip device apart to effect a draw, means to move said working device and grip device toward each other,-a drawn stock discharge member movable into' and out of operative position, means to latch said member in retracted or inoperative position, means tending to move said member to operative position upon relative movement of said devices away from eachother, means associated with one of said devices to release said latch, means tomove said member to retracted or inoperative position, and

means responsive to the position'of said latch to control said means to move said devices toward each other.

A WALLACE Ea KERR. 

